In recent years, commercial and residential lighting applications include an array of LED chips or assemblies as the light source in place of the conventional incandescent lights or HID lights.
LEDs are more efficient forms of lights than conventional light sources although LEDs are known to have various problems and concerns. LEDs can be difficult to focus and direct the light to a selected area. LEDs emit light in all directions from the circuit board and require a lens or prism to control the direction and distribution of the light. Individual LEDs do not provide sufficient light so that large numbers or arrays of LEDs are required to illuminate the desired area.
LEDs also require a mechanism for dissipating the heat that is inherently produced by the LED. Various structures are proposed for use with LED arrays that include heat sinks, cooling fins, and the like, to dissipate the heat and prevent damage to the LED and circuit board.
U.S. Patent Publication No. 2012/0025711 to Best et al. discloses an outdoor overhead lamp assembly having a plurality of LED modules within the lamp. The modules are mounted to inclined surfaces for directing the light in a selected direction. The inclined surfaces are molded into the housing of the luminaire so that the position of the LED modules is fixed.
U.S. Patent Publication No. 2012/0014099 to An et al. discloses a lighting system having a plurality of LED modules mounted to a base and a heat sink extending outwardly from the base as shown in FIG. 4.
U.S. Patent Publication No. 2011/0291588 to Tagare discloses a light fixture having an array of self-contained LED tiles. The tiles have geometric shapes for joining the LEDs together in selected patterns.
U.S. Patent Publication No. 2011/0194279 to Kuo discloses an LED lighting device. The lighting device includes a housing and a circuit board supporting LED lamps. A cover is mounted to the housing to retain the LED modules in the housing.
U.S. Patent Publication No. 2011/0122632 to Ku et al. discloses an LED unit having a lens. The lens has an incidence surface, an emission surface and a light-reflecting face between the incidence surface and the emission surface.
U.S. Patent Publication No. 2011/0044038 to Mo discloses an LED lamp having a plurality of LEDs mounted in a supporting plate. The LEDs include first LEDs disposed on a top surface of the supporting plate and a plurality of second LEDs disposed on the bottom surface of the supporting plate and surrounding a light reflecting member.
U.S. Patent Publication No. 2010/0157594 to Yang et al. discloses an LED lamp having a semi-spherical lamp body and a plurality of LEDs embedded on an outer surface of the semi-spherical body.
U.S. Patent Publication No. 2010/0103668 to Leuken et al. and assigned to Hubbell discloses an LED with a plurality of luminaire modules. The luminaire modules in this device are mounted in a fixed position.
U.S. Patent Publication No. 2008/0080188 to Wang discloses a modular assembly for an LED lamp. The LED modules have an LED mounted to a base which is attached to a heat sink as shown in FIG. 2.
U.S. Pat. No. 8,075,163 to Xiao et al. discloses an illumination lamp and rotatable light emitting module. The module as shown in FIGS. 2 and 3 include an LED array mounted to a base plate. The base plate is pivotally mounted to a support so that the orientation of the array can be adjusted with respect to the housing.
U.S. Pat. No. 8,061,868 to Dubord discloses an adjustable LED lighting system. The lighting system includes an LED array mounted to a printed circuit board as shown in FIG. 2. The housing surrounding the LED includes a cylindrical housing that can be broken in two pieces along a tear line that extends diagonally through the cylindrical housing. The top portion of the housing can be rotated with respect to the bottom portion and snap fit together to angle the lens in a selected direction as shown in FIG. 6.
U.S. Pat. No. 7,997,768 to Zheng discloses an LED lamp having an upper base plate and a lower base plate with a plurality of LED modules between the plates. Each module has a heat sink sandwiched between the two base plates and a lens engaging the bottom surface of a conductive cylinder enclosing the LED module.
U.S. Pat. No. 7,488,097 to Reisenauer et al. discloses an LED lamp module designed to be retrofitted into an existing incandescent light fixture. The module includes a circular metal core with an LED and printed circuit board. A second surface of the metal core is configured to contact a fixture and heat generated by the LED conducted to the fixture.
While the prior lighting devices are generally suitable for their intended purpose, there is a continuing need in the industry for improved LED lighting devices.